The permanent redirect: when to use 301, how browsers cache it, and 301 vs 308
Runs in your browser. Nothing you type is sent anywhere. Updated on 25 Oct 2026.A 301 tells every client that the address has moved for good and the new one is in the Location header. RFC 9110 section 15.4.2 lets a client change a POST into a GET when it follows one; use 308 when the method must stay the same.
Open the page with 301 Moved Permanently already selected.
Read "When to use it": renamed pages, a domain move, forcing HTTPS or the www prefix.
Read the note on caching: browsers can keep a 301 until their cache is cleared.
Choose your server or framework under "Send this code in" and press Copy snippet.
Search engines move ranking to the new address, and browsers cache a 301 hard, so test a new redirect with 302 first and switch once it is right.
This HTTP status codes reference lists every registered code from 100 to 511, plus the unregistered ones that nginx, Apache, Laravel and Cloudflare return. Each entry says what the code actually means, when to send it, whether a cache may store the response without cache headers, whether a redirect changes the request method, and which RFC defines it.
Two details most lists get wrong are included here. Cacheability is not a yes or no: RFC 9110 section 15.1 names twelve codes a cache may store with no explicit headers at all, which is why an accidental 404 can stick. And redirects differ: 301 and 302 let a client turn a POST into a GET, 303 always does, while 307 and 308 must repeat the method and body exactly.
Every common code comes with a copyable snippet for raw HTTP, Express, Fastify, FastAPI, Go and PHP, including the header that code requires, such as WWW-Authenticate on a 401 or Allow on a 405. Nothing is sent anywhere; the whole table is in the page.
The rest of the article, and all 6 questions about HTTP Status Codes, are on the HTTP Status Codes page.
Use 401 Unauthorized. It means the server does not know who you are, so a missing, expired or wrong credential belongs there. Use 403 Forbidden only when you know who the caller is and are still refusing. The specification wants a WWW-Authenticate header on every 401.
RFC 9110 section 15.1 lists 200, 203, 204, 206, 300, 301, 308, 404, 405, 410, 414 and 501 as heuristically cacheable, and RFC 7725 adds 451. A cache may store those with no Cache-Control or Expires header, which is why a temporary 404 can persist. Every other code needs explicit cache headers.
The specification does not allow it, but nearly every browser does exactly that for 301 and 302. A 303 always turns the next request into a GET. If the method and body must survive the redirect, use 307 for a temporary move or 308 for a permanent one.
418 I'm a Teapot comes from RFC 2324, an April Fools' joke from 1998 about a coffee pot protocol. A 2017 proposal to reuse the number was withdrawn after objections, so it stays reserved in the IANA registry and must never be used for a real meaning.
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